Blood supply in the developing and post natal rat soft palate. Foetal and post natal rats were perfused with a carbon suspension and cleared in methyl salicylate to display the blood supply of the developing and formed hard and soft palates. The arterial blood supply of the soft palate was from the pharyngeal artery, a branch of the pterygopalatine artery; and from the tonsillar artery, a branch of the external maxillary artery. The pharyngeal artery could be recognised from 14 days post insemination and reached its adult configuration on the 17th day p.i. The tonsillar artery was seen from the 18th day. In the hard palate the blood supply was as described by other authors.


Normal histology of the human soft palate. The histology of the human soft palate seen in four whole soft palates and four mucosal biopsies has been described, with an emphasis on the elastic fibres. Striking features were the presence of much fat, thick interglandular connective tissue septa, considerable elastic tissue, and a complete absence of taste buds.


NDEB evaluates four years' experience.

NDEB evaluates four years' experience.


How does the professional cope with inflation? Part III. A tax lawyer's viewpoint.


Current developments in periodontics: part II. The whys and wherefores of periodontal surgery.


Wound healing and its periodontal implications.


Simulated dry socket: delayed healing of extraction wounds in rats.


Editorial: New Year's message from the president.


Influence of the collection and transport of specimens on the recovery of bacteria from peritonsillar abscesses. In 30 patients with peritonsillar abscesses, pus was obtained by aspiration and by taking a swab after incision; bacterial recovery was compared. Although processed in the laboratory within 2 h, swab speciments gave results comparable to syringe specimens in only 9 of 13 patients with beta-hemolytic streptococci and 7 of 25 patients with anaerobic bacteria. Both kinds of microorganisms were lost in some cases but appeared as additional flora in others. The poor results from the swab technique was ascribed to overgrowth of respiratory flora contaminating the sample after incision. In aspirated pus kept in the syringe, or transferred to anaerobic transporters, the microbial flora was unchanged for 24 to 48 h. Some anaerobes also survived on agar slants for 24 h, but specially designed anaerobic transporters are recommended.


Attributes of potential utility in differentiating among "group H" streptococci or Streptococcus sanguis.


Physiological classification of oral viridans streptococci. The human mouth harbors large numbers of a variety of greening streptococci. For many years the classification and nomenclature of these organisms have been confused, but recent studies have clarified the situation considerably. Five distinct species can be distinguished among the oral streptococci S mutans, S sanguis, S mitior, S milleri, and S salivarius, and these may be identified using a simple scheme consisting of seven physiological tests. Further subdivisions within these species may be achieved using serological methods. A small number of oral streptococci remain which cannot easily be identified with existing schemes. These may represent additional species that, as yet, have not been adequately described. There seems little justification for continuing the practive of calling all alpha-hemolytic streptococci simple "Streptococcus viridans".


Comparative chemical compositions of cell walls of Streptococcus mutans.


Antigens and surface components associated with virulence of Actinomyces viscosus. We have isolated a specific cell wall antigen of high molecular weight which appears to be unique to virulent strains of A viscosus and A naeslundii. The antigen is composed of two parts: a polysaccharide moiety containing 6-DOT as the major sugar and determinant of serologic specificity, and a small peptide bearing some resemblance to the peptidoglycan. Other data indicate a positive correlation between the presence of this antigen and an extrachromosomal piece of DNA having most of the properties of a bacterial plasmid. The specific function of the 6-DOT antigen in disease production is not known, but its clear association with virulent strains suggests the possibility of monitoring specific populations of oral actinomycetes.


Streptococci of the oral cavity other than Streptococcus mutans: an evaluation of some present knowledge.


Antigens from Actinomyces species and their value in identification. Actinomyces have a complex antigenic structure that includes neutral cell wall carbohydrate and some polypeptide containing charged antigens. Wall carbohydrate can be prepared in a relatively pure form from cell walls or by DEAE Sephadex chromatography of acid extracts and supernatant culture fluid. Charged antigens are generally eluted in groups by batch-elution from columns. Cell wall carbohydrate can be responsible for species-specific reactions and cross-reactions, and strains may possess more than one cell wall carbohydrate determinant. The charged antigens also can be species specific, but they cause some cross-reactions, particularly those between the A israelii serotypes. Autoclave extracts of strains, tested against antiserums reacting with cell wall carbohydrate, may be valuable in routine identification of isolates.


Cellular fatty acid composition of Streptococcus mutans and related streptococci. The cellular fatty acid composition of 18 strains of Streptococcus mutans and 17 isolates of related streptococci were examined by gas-liquid chromatography. The cultures could be divided into two distinct groups on the basis of their fatty acids. The first group, which included S mutans and S salivarius, contained palmitic (16:0), octadecenoic (18:1), stearic (18:0), eicosenoic (20:1), and eicosanoic (20:0) acids. The presence of the two 20-carbon fatty acids distinguished S mutans and S salivarius from all of the other species. Two of the S mutans cultures were further distinguished by the presence of 19-carbon and 21-carbon cyclopropane acids. The second group included S sanguis, S mitis, S uberis, and a culture of Lancefield group C streptococci. The percentages of the major acids (16:0, 18:1, and 18:0) found in these species were essentially identical. A culture of Lancefield group E streptococci contained large amounts of 16:1 and 18:1 and small amounts of two unidentified acids which were not present in any of the other cultures.


Examination of the test for compressive strength applied to zinc oxide eugenol cements. The distribution of compressive strength results for a zinc oxide eugenol cement is negatively skewed. However, removal of a small number of outlying low results converts the distribution to a normal one. Crosshead speed and friction at the anvil have no significant effect on results, but compressive strength is a function of the diameter-length ratio of the cylinder and increases with this ratio.


Effect of diphosphonates on root resorption.


Development of scales to measure provider attitudes toward expanded duty dental auxiliaries. Much of the research on attitudes toward utilizing EDDAs has been rather haphazard in its measurement aspects. Examining responses to single items or summing across a series of items without any empirical rationale for such summing cannot be justified given current knowledge about measuring attitudes. The scales developed here are appreciably better from a psychometric point of view than scales reported in the dental literature to date. The use of standardized measuring instruments would facilitate cross-study comparisons. Such a process is presently not feasible because each researcher is using his own idiosyncratic scales of unknown psychometric characteristics. The three scales developed here to measure (1) the value of expanding auxiliary functions, (2) patient reaction to the use of EDDAs, and (3) satisfaction with changed dentist role may permit more standardized measurement of at least some aspects of provider and future provider attitudes toward the utilization of expanded duty dental auxiliaries.


Correlation between deciduous tooth size.


Enamel corrosion produced by zinc phosphate dental cement. The application of a phosphoric acid solution or of a zinc phosphate cement mix on enamel surface causes alteration of its structure. The lesions of the enamel are cavities of irregular shapes that might retain debris. In view of the high solubility of disintegration of the cement, those cavities can be considered potential sites of plaque installation and initiation of carious processes.


Sex ratio in amelogenesis imperfecta.

Sex ratio in amelogenesis imperfecta.


Editorial: Toward creative education.

Editorial: Toward creative education.


Quantitative stereological investigations of porous alumina implant biomaterials. We made several conclusions from this study on a candidate porous alumina bioceramic. First, the volume fraction of porosity varied from 64 to 79%, whereas Archimedes density shows 62% porosity. Second, the mean lineal intercept and tangent diameter varied from 0.048 to 0.058 cm and 0.034 to 0.040 cm, respectively, and did not provide a good concept of the minimum pore size neck dimensions for the specimen. Third, the pore-size dimension varied from 0.0185 to 0.1157 cm which indicated a minimum pore neck size large enough for tissue ingrowth and ossification if located in bone. Fourth, the pore structure was totally interconnected with considerable side branching and multi-interconnections. Fifth, the serial sectioning of the porous alumina ceramic biomaterial provides considerable insight into the critical features of the material as a candidate for a surgical implant material and a better understanding of the relationships between two-dimensional and three-dimensional structural components.


Effects of cement bases on the stresses and deflections in composite restorations. A model was used to investigate stresses and deflections in cement bases and in a composite restorative material induced in a posterior Class I restoration. Deflections in the composite were highest when it was supported by a base with a low modulus; however, the maximum tensile stress (12 MN/meter2) occurring in the composite restoration at the interface with the base was well below the maximum tensile strength of most composite materials (30 to 40 MN/ meter2). Tensile and shear stresses occurring in the cement bases were of sufficient magnitude to exceed the strength of the cement when a 1.5-mm layer of zinc phosphate cement (base consistency) was supported by a 0.5-mm layer of ZOE lining material. Lowest values of stress were observed when a 2-mm layer of a zinc polyacrylate base was used to support the composite restoration. An ideal situation would be to have a cement base with a modulus of elasticity equal to that of the composite material. Finally, the maximum stress and deflection values obtained here can be easily exceeded in a clinical situation when wider variations can be easily introduced, making the choice of a cement with the proper modulus even more critical.


Technique for measurement of sarcomere length of striated muscle.


Relationship between fluoride concentration in enamel, DMFT index, and degree of fluorosis in a community residing in an area with a high level of fluoride. The object of the present study was an attempt to relate fluoride concentration in enamel, caries experience, and the degree of fluorosis in a community residing in an area with a high level of fluoride. A significant difference was found between the male and female samples for the F and D parameters. A positive correlation was established for the male participants between DEGF and F, and a negative correlation between age and F. These correlations were not found for the female participants. Because of the low and narrow range of DMFT indexes, no correlation involving this parameter could be established.


Impact of a conference institute taught by individualized instruction. The results indicate that a CI based on individualized, flexible instruction succeeded in aiding acquisition and retention of new knowledge, fostering interactions between dental educators interested in educational research, augmenting a positive feeling toward educational research, and changing the subsequent professional activities of the participants. Data collected and analyzed during a five-year period following a five-week CI on educational research indicate the following: 1. The participants acquire, retain, and use an appreciable amount of information taught in a brief time period. 2. Instructional materials sent in advance for voluntary study have little influence on acquisition of knowledge. 3. Informal interactions between participants are an important part of the learning process at a CI. 4. Activities at the home institution do not shift to new broad categories to any appreciable extent, but changes in specific activities directly related to the goals of the CI were observed.


Xeroradiography in dentistry.

Xeroradiography in dentistry. Extensive review of the literature reveals that the diagnostic benefits of xeroradiography in medicine are rapidly being recognized. It is viewed with particular interest by clinicians managing neoplasms of the laryngopharyngeal, mammary, and joint regions. Xeroradiography is a definite aid in cephalometric analysis. Examples of use have been presented. The main disadvantage of xeroradiography in dentistry is that of slow-speed developing in comparison with that of our current silver halide films. This becomes significant when dealing with intraoral films. However, the only disadvantage that we have experienced with xerocephalometrics is that of head orientation. Because our radiology department is not equipped with a wall mount for proper alignment along the horizontal and vertical planes, the head position must be estimated with a plumb line. Very often, therefore, the head may be tipped in one direction or another. This, however, is not difficult to correct. I have noted several definite advantages that include: --Sharp, clear-cut contrast (because of the edge effect), which enhances image quality. --Simplified viewing (no need for view boxes). --Less radiation than that required for conventional radiographs. Because of the benefit of multiple-tissue diagnosis on one radiograph, there is no need to take multiple radiographs to record tissues of different densities, with the possible exceptional of special situations in tomography. --Dry, automatic processing, therefore, eliminating the need for mixed chemicals and darkroom. --Less cost to produce a xeroradiograph than a conventional radiograph because of the lower cost of materials and equipment (for example, no darkroom requirement). The Russian investigators reported an eightfold reduction in cost. Xeroradiography (from Greek word xeros meaning dry) is a radiographic process in which the quality is critically dependent on the potential of the surface charge on the plate, the amount of radiation exposure, and the conditions of development, all of which must be carefully controlled. This technique is gaining general acceptance. Special courses are being offered to teach technicians this process. I believe we have come on a new horizon in diagnostic radiography. Only through further investigation and research will we be better able to delineate the exact role of xeroradiography in dentistry.


Sequential electron microscopic healing study of grafted palatal mucosal. Human palatal mucosa may be glycerolized, frozen, thawed, and autogenically transplanted with success after a storage period. Although tissue damage is observed, both on a light and electron microscopic level, this is not clinically significant. This damage is attributed to the glycerolization, freezing, and thawing processes. As evidenced primarily by our ultrastructural study, regeneration of grafted epithelium is effected via the basal cell layer. The formation of intracytoplasmic vesicular structures and alterations in both the basal lamina and intercellular substances may play a significant role in the regenerative process. The electron microscope has served to elucidate changes in regenerating cells that have not been previously observed by light microscopy.


Dentistry and the county home resident: a statewide survey. A flow chart (illustration) depicts the delivery process whereby county home residents either receive or do not receive dental treatment. Also included are the major findings of the survey, given in triangles A, B, and C. The initial step involved in this delivery process is that of recognizing a need. If the need is not recognized, it remains unmet and the patient receives no treatment (terminate). If the need is recognized, a treatment decision is required. If the decision is negative, the need remains unmet and the patient receives no treatment. If the decision is positive, the patient proceeds toward the goal of receiving dental treatment. However, potential delivery problems exist and the patient may have to overcome one or more of these before proceeding toward the goal. If problems do exist and are not resolved, the patient either does not receive treatment or treatment is delayed until satisfactory solutions are found. The first finding, A, shows that more than 72% of dental needs were identified because of some dental emergency experienced by the patient, 39.3% of needs were identified through routine checkups, 16.4% by a county home requirement, 14.8% through a state requirement, and 4.9%, "other." The second finding, B, shows that the county home steward makes the decision about whether dental treatment should be rendered in more than 85% of the homes. Physicians made 54.1% of the dental treatment decisions; nurses, 31.1%; dentists, 26.2%; patients, 24.6%; patient's family, 13.1%; supervisor or trustee, 4.9%; and "other," 3.3%. The third finding, C, represents delivery problems. More than 44% of the stewards said that the patient's mental or physical disabilities were a delivery problem; 39.3% indicated availability of dentists; 36.1% said reluctance of patient; 19.7% responded inadequate funding; and 14.8% indicated "other." A hypothetical county home resident can be dentally characterized as an emergency patient whose need for treatment is determined by a county home steward, and the main problem in obtaining treatment, according to the steward, is the patient's own inability to receive treatment because of mental or physical disabilities, or both.


Fracture properties of human enamel and dentin. Fracture in enamel is anisotropic with respect ot the orientation of the enamel rods, with Wf for fracture parallel to the rods being 0.3 X 10(2) J/meter2 but on the order of 2.0 X 10(2) J/meter2 for fracture perpendicular to the rods. Fractographs of enamel showed that the enamel rods behaved as integral units during controlled fracture. A model was proposed to explain the fracture properties of enamel involving the assumption that the hydroxyapatite crystals did not fracture but that their orientation determined the fracture properties. Dentin was also anisotropic, with fracture parallel to the dentinal tubules being the strong direction - Wf was 5.5 X 10(2) J/meter2 for fracture parallel to the tubules, but 2.7 X 10(2) J/meter2 for fracture perpendicular to the tubules. Wf for dentin was of the same magnitude as the high strain rate Wf found for bone (2.0 X 10(2) J/meter2 [ref 3]). The data obtained in this investigation indicated that dentin and enamel are brittle substances and that forces occasionally imposed during mastication or bruxism probably are capable of initiating fracture when the normal anatomy of the tooth has been altered by cavity preparation. As consequence, the design of cavity preparations should include considerations to reduce stress concentrations and thus improve the practical fracture strength of tooth structure.


Use of multiple artificial mouths to predict cariostatic effects.


Excretion of barbiturates into induced parotid saliva of the rat. On the basis of the results presented in this study, it has been shown that the five barbiturates studied are excreted into the parotid saliva of the rat. Furthermore, it has been shown that the salivary excretion of these agents, as indicated by their S/P concentration ratios can be correlated with the lipid solubility as indicated by the L/W partition coefficient, and can be correlated to a lesser extent with the degree of drug ionization and plasma protein binding.


High blood pressure detection: a new public health measure for the dental profession. Detection of high blood pressure can be a major public health service contribution by the dental profession. The pioneer program at Fairleigh Dickinson University, in conjunction with the Bergen County Health Department and the Bergen County Dental Society, is encouraging dentists to participate in the National High Blood Pressure Program. Participants are urged to measure the blood pressures of all their adolescent and adult patients and to refer those with sustained elevated readings to their physicians, preferably by the arrangements of appointments.


Editorial: The life of a manuscript from writer to publication.


Subcondylar impaction of a third molar with a dentigerous cyst resulting in a chronic cutaneous sinus: report of case.


Molar size sequence in the Tarahumara Indian.


Abbreviated periodontal examination.

Abbreviated periodontal examination. The prevention, detection, and treatment of periodontal disease should be among the foremost goals of dentistry. When a systematic examination is used, detection of the disease need not be a lengthy or cumbersome procedure. The mesiofacial aspect of every tooth should be probed and recorded. The integrity of all furcations should be carefully checked, mobility patterns should be recorded, and the patient should be examined for any mucognigival problems. If any of these problems are detected, the clinician must decide whether he will treat the problem himself or refer the patient to someone else. The important thing is that periodontal disease has been recognized and can, therefore, be dealt with.


Relationship between tooth size and body size in American Blacks.


Acrylamide gel electrophoretic studies of extracellular sucrose-metabolizing enzymes of Streptococcus mutans. This study explored the use of acrylamide gel electrophoretic methods to determine the numbers and types of extracellular sucrose-metabolizing enzymes produced by particular strains of S mutans. Strains HS-6, SL-1, FA-1, and NCTC 10449 were cultured in a chemically defined medium and the extracellular proteins elaborated by the organisms were isolated and subjected to acrylamide gel electrophoresis. Patterns of protein components and sucrose-metabolizing enzymes were then delineated. Three types of sucrose-metabolizing enzymes were observed. One type was involved in the synthesis of polysaccharides that were insolubilized in the gels. Another type was involved in the synthesis of water-soluble polysaccharides. A third type was involved in the splitting of sucrose into reducing sugars without polysaccharide synthesis. Each pattern was distinctive with regard to the numbers, proportions, and types of enzyme components present and their migratory characteristics. From two to at least six components were observed amont the enzyme activity patterns per strain. Extracellular protein patterns showed from 12 to 20 components per strain. Comparative data on growth in the chemically defined medium and Todd-Hewitt broth were also presented. Better growth levels were obtained in all instances with the chemically defined medium over comparable periods of time.


Quasimonochromatic radiation for dental radiography. Because of the greater sensitivity of commonly used dental films near 40 kv and the inherently greater contrast between bone and other oral tissues that is achieved at lower energies than those conventionally used, a considerable reduction of radiation exposure can be obtained by the use of those quasimonochromatic photons whose energy lies between 30 and 40 kv. The simplest and clinically most efficacious and econimical method of obtaining this quasimonochromatic radiation using fixed-anode tubes involves the use of Ce, 0.008 inch in thickness, as a band-pass filter, with reduction of skin exposure by a third to a half. The considerable dose reduction achieved at an increased exposure time of only 1.2 seconds is significant in view of the fact that both a greater percentage as well as a greater number of people are receiving radiation for oral diagnosis every year. Since the quasimonochromatic rays produced are less energetic than much of the radiation in the unfiltered beam, the radiation doses from scattered radiation to skull, bone marrow, and gonads also are reduced. In addition, the softer photons result in less Compton scattering, reducing the fog and improving the diagnostic quality of the film. Quasimonochromatic radiation may also be used to enhance the contrast wherever iodine contrast medium is needed since iodine absorbs very strongly above its absorption edge near 33 kev, suggesting another use of this technique in the area of oral diagnosis.


In vitro interactions between the surfaces of enamel white spots and calcifying solutions. The treatment of white spot enamel lesions with a saturated DCPD solution followed by a high fluoride topical application appeared to produce a surface coating consisting mainly of spherical particles that filled in the honeycombed-etched surface of the untreated enamel white spot. The conditions used in these pilot studies were not ideal to take advantage of the DCPD and fluoride reaction to form FAP. Additional study is warranted on the solution composition and application time along with identification of the reaction products formed.


A physiochemical approach to the study of amines as antiplaque agents. Alkyl and aromatic amines were evaluated for inhibitory activity against S mutans 6715. Only the alkylamines were active and this may be due to their greater basicity. The agents that showed good activity were decylamine, dodecylamine, tetradecylamine, and hexadecylamine. In addition to the free bases, the hydrochloride and hydrofluoride salts were also tested for inhibitory activity and the same four agents were shown to be most active. These agents appear to hold good promise as antiplaque agents against S mutans 6715, therefore, further in vitro studies against other plaque-forming bacteria and toxicological and clinical evaluation seems to be warranted to determine the best clinical agent.


Traumatic cyst of the jaws: report of 30 cases. A clinicopathologic study was made on 30 cases of the traumatic bone cyst of the jaws, and these observations were recorded. --The lesion is one of skeletal-wide distribution, but in the jaws it occurs most frequently in the posterior portions of the mandible. --The majority of cases are not associated with trauma, and the lesion is most commonly detected in routine radiographs. --The median age of this series of patients was 20 years, and the majority of patients in this series white men. --Histologically extravasated red blood cells, degenerating fibromyxomatous tissue both inside and outside of bone, hemorrhagic membranes, and other changes consistent with degenerative processes were observed. --The origin of the traumatic bone cyst was not determined in this study, but histologic evidence pointed toward a degenerative process that also could not be adequately explained; therefore, the more general term solitary bone cyst is suggested for use. --Treatment of the solitary bone cyst consists essentially of exposing the lesion and mild curetting to produce a clot formation that will subsequently organize and fill in with new bone.


Type B (serum) hepatitis and dental practice. Council on Dental Therapeutics.


Characteristics of an in vitro dental pellicle. Procedures developed for in vitro pellicle formation in intact enamel proved useful for relating qualitiative characteristics of dental pellicle to a number of factors. Coronal surfaces of extracted human molars from experimental and control groups were pumiced, sterilized, and incubated for two hours at 37 C in parotid saliva and distilled water, respectively. Pellicle proteins were desorbed sequentially with water and 0.2 M sodium phosphate, with a pH of 7.0. Polyacrylamide disc electrophoresis of the desorbates yielded distinct patterns, indicating selective adsorption of proteins from saliva, varying affinity to enamel, and the presence of proteins not acquired in vitro from saliva. Certain pellicle components, including amylase and IgA, showed a relatively weak affinity for enamel and were eluted in part by water; other proteins were desorbed only by phosphate buffer. Anionic electropherograms of the phosphate desorbates showed an increase in the two most anodic proteins relative to corresponding salivary bands. An intense anodic protein and two minor bands were eluted by water or buffer from the surface of control as well as experimental teeth but not from teeth coated with sealants. Serum albumin and alkaline phosphatase were identified as components of the extra-salivary material. Further investigation of the sources and functions of the constituents of the protein layer generally considered as "acquired" dental pellicle appears warranted.


List of classified dental materials and devices revised to Jan 1, 1976. Council on Dental Materials and Devices.


Certification program for dental materials: list of certified dental materials and devices revised to Jan 1, 1976. Council on Dental Materials and Devices.


Stress concentrations at the apex of pinned, implanted teeth. Stress in the alveolus at the apex is reduced when the implant is held by a pin through the alveolar wall. This stress reduction is effected by transfer of part of the coronal force to the alveolar wall by the pin. Pin positions centrally located between the apex and the alveolar crest provide the greatest reduction of stress concentration in the alveolus at the apex. Since the bone is especially fragile near the alveolar crest, care must be taken when the pin is positioned in this region. Positioning the pin near the apex has the least effect on reducing the stress in the alveolus at the apex. Although no data were obtained relating to stress in the alveolar wall at points of pin penetration, results given here do indicate that from 7 to 30% of the intrusion component of the coronal force is transmitted to the alveolar wall by the pin. Additional research is needed to determine the effects of stress at the pin through the alveolar wall because of load transfer by the pin from the implant to the alveolar wall. The situation in the alveolar wall would be one of creation of a completely unnatural stress rather than reduction of an existing stress, as was the case at the apex. Whether the reduction of stress at the apex and the creation of stress at the pin through the alveolar wall are of physiological benefit is a question that must yet be answered.


Production of plaques and initiation of caries in vitro.


Continuing education. Course listing for January through June 1976. Bureau of Dental Society Services. Council on Dental Education.


Regression-based techniques for estimating fluoride in surface enamel in large study groups.


Dentin formation in periodontally diseased teeth.


Letter: Ada-agd unity.

Letter: Ada-agd unity.


Letter: Prophylaxis not mystery.

Letter: Prophylaxis not mystery.


Letter: Sargenti's response.

Letter: Sargenti's response.


Letter: Where is centric?

Letter: Where is centric?


Letter: Third party.

Letter: Third party.


Dimethacrylates derived from hydroxybenzoic acids. Since the color stabilities and durabilities of current composite and pit and fissure sealant resins need improvement, it is worthwhile to evaluate innovations that might accomplish this goal. Accordingly, three crystalline dimethacrylate monomers with low melting points were prepared from the isomeric hydroxybenzoic acids and 2-bromo-ethyl methacrylate. These monomers can be purified by crystallization and liquified by admixture in various proportions to obtain a polymerizable liquid of suitable viscosity at room temperature. In contrast to the analogous dimethacrylate monomers that were derived from the phthalic acid isomers, these aromatic ether-ester dimethacrylates do not form colored charge-transfer complexes with tertiary aromatic amine accelerators. These monomers and their polymers should be elevated for use in composites and pit and fissure sealant formulations.


Letter: Reciprocity.

Letter: Reciprocity.


Lists of products evaluated by the Council on Dental Materials and Devices and the Council on Dental Therapeutics.


Letter: Supply and demand.

Letter: Supply and demand.


Letter: Times' insert negative.

Letter: Times' insert negative.


Preview of dentistry in the United States-1985?


Point and interval estimation in the combination of bioassay results. A procedure for combining evidence from different biological assays is shown to be equivalent both to generalized least-squares and to maximum-likelihood estimation. By appropriate nesting of hypotheses, the likelihood function can be used to test the agreement between the assays and to obtain probability limits for the combined estimate of potency. The properties of these limits are examined, with particular reference to the situation, unusual but not impossible in practice, in which the values of relative potency that they define consist of several disjoint segments instead of a single interval. The connection with general theory of estimating linear functional relations is pointed out.


Investigation of cross-infection in isolation wards of different design. A survey was conducted in seven hospitals to assess the risk of cross-infection with the highly infectious air-borne diseases, varicella-zoster and measles, in isolation wards of different design. Existing wards and isolation techniques were found to afford a high degree of protection, but there was considerable variation in the incidence of cross-infection related to ward structure, ward practice and the availability of trained staff. Recommendations are made for the design of new isolation wards and for safe practice.


Role of rubella in congenital malformations in India. In the present study rubella HI antibodies were determined in cases of congenital malformation and bad obstetric history to determine the role of rubella in such cases in India, as it has been reported to be rare in Japan in contrast to Western countries. The incidence of antibodies was statistically significant in cases of congenital eye, C.N.S., visceral and miscellaneous malformations and cases of spontaneous abortion and still-birth compared with controls of matching age groups. This is further supported by the demonstration of IgM antibodies in seven cases of congenital malformations and ten cases of spontaneous abortion. Our findings show that congenital rubella is not rare in India.


A contribution to the primary reconstruction of the upper lip and labial commissure following tumour excision. Two procedures for the primary reconstruction of the upper lip and corner of the mouth following tumour excision have been described in the paper presented. One method represents a modification of Burow's technique (1855) for the reconstruction of the lower lip, which is very suitable in the reconstruction of the lateral border of the upper lip. The second procedure is best suited for the remoulding of the area of the angle of the mouth. The tumour is excised in a crescent-shaped manner, and the missing upper and lower lip reconstructed by means of a horizontal incision in the cheek, and de-epithelisation of two triangular areas which are covered with undermined buccal mucosa. The incision lines described have been illustrated in two cases.


Late results after advancing the mandible by sagittal splitting of the rami. 38 patients have been followed up for at least 2 years, and in the mean 5 years after surgical correction of retrognathia. The technique used was the sagittal splitting of the rami (Obwegeser 1955, 1957) usually with the modification of the lateral cortical bone cut of Dal Pont (1959). 26 patients showed no changes compared with the early postoperative result. In 8 other cases, the horizontal overjet increased up to 3 mm without impairment of the aesthetic or functional result. Therefore the operation may be considered successful in 90% of cases. Four severe relapses were noted. They are at least partially caused by poor repositioning of the condyle-bearing segment during operation. Reduced function of different degrees was seen at the late check-up in 20% of the mental nerves. 45% of the patients have cracking in the temporomandibular joint. Causes and possible late consequences are discussed. To conclude, the sagittal splitting of the rami for the forward movement of the mandible as the standard method of our clinic seems justified.


New guiding principles in the treatment of clefts. Breathing through the nose with the mouth shut is essential for the normal development of the facial region related to the mouth and nasal cavities and for the normal development of the two cavities named. Surgical treatment of unilateral total cleft practised hitherto calls for the closure of a cleft in the lip and a cleft in the alveolar ridge at the same surgical intervention. In the great majority of cases a combined intervention closes the respiratory pathway, which was established through the cleft nasal floor and alveolar ridge after birth. From the first surgical intervention on, the child is forced to breathe through the mouth. The disruption of the normal functional development mechanism causes the formation of the characteristic physiognomy of a child with a cleft. The correct treatment as presented in this paper, must consistently observe, in addition to other no less important principles, the primary principle: it is essential for a child with cleft to be made to breathe through the nose with the mouth shut, as soon as possible. The operative plan of treatment must help a child with a cleft to create, by utilizing the natural development abilities, and with minimal application of trauma, the same conditions for the functional development mechanism as are possessed by a healthy child of the same age. The enclosed evidence proves the validity of the described guiding rules, and affirms again the well known principle that only normal function produces normal form.


Visor osteotomy to increase the absolute height of the atrophied mandible. A preliminary report. A method of operation is described whereby the alveolar ridge of the mandible is osteotomised and moved on the principle of a visor. The two parts are fixed together with wires, thus increasing the absolute height of the alveolar ridge of the mandible.


Maxillary alveolar hyperplasia, diagnosis and treatment planning. Literature pertaining to studies of the vertical relationships of the facial skeleton, the dentition, and the lips is reviewed. A surgical procedure for superior repositioning of the total maxillary alveolus is presented. The usefulness of the procedure to correct maxillary alveolar hyperplasia is illustrated with two case reports.


Topographical anatomy of the total osteotomy of the midface. In this study, the operating conditions for total osteotomy of the middle part of the face have been simulated in a cadaver and the topography of the organs at risk has been examined. The area of the maxillary tuberosity is the region which is mainly exposed to considerable injury to vessels; here an uncontrolled fracture as compared with a systematic osteotomy is the safer method under the given anatomical conditions.


Bacterium anitratum bacteremia in a chronic myelogenous leukemia with blastic transformation patients.


Congenital nephrotic syndrome.

Congenital nephrotic syndrome.


Prevalence of intestinal parasites in children on a Taiwan offshore island determined by the use of several diagnostic methods.


An experimental neuroanatomical study of the corticospinal system of the albino rat.


Cholinergic influences on the morphine-induced running response in the mice.


Implementing the definition of nursing practice: case study. I. Nursing intervention for the patient with duodenal ulcers.


Implementing the definition of nursing practice: case study. II. Nursing intervention for the patient with chronic organic brain disease.


Surgical removal of orbital osteoma; case report. Thr authors report a patient with a large orbital osteoma causing marked physical deformity and diplopia but with preservation of visual acuity. A combined transorbital and transcranial operative approach was used for total tumor removal and cosmetic repair.


Implementing the definition of nursing practice: case study III. Nursing intervention for the patient with diabetes mellitus.


Implementing the definition of nursing practice: an overview.


Professional nursing practice and the hospital milieu.


An approach to teaching empathy.

An approach to teaching empathy.


New York State Nurses Association: report of the Task Force to Study the Nursing Home Situation.


Abuse and neglect.

Abuse and neglect.


"Role relationship...".

"Role relationship...".


Commitment to standards ends in the courts.


Letter: Licensing of specialists.

Letter: Licensing of specialists.


Letter: The overproduction of oral surgeons.


Letter: The legal definition of oral surgery.


Editorial: Games people play.

Editorial: Games people play.


Mechanisms of early maxillary growth-implications for surgery. Previous studies of the effects of surgical techniques on facial growth (with one exception) have been done in dogs, pigs, rabbits, and rats; the phylogenetically closer nonhuman primate serves as a better model. Current data, obtained from resection of the nasal septum in baboons, indicate that proper coordination of timing and surgical technique can cause arrest of growth in the upper part of the face.


Secondary correction of nasal abnormalities associated with cleft lip. Approximately 30% of patients will require a second operation for correction of nasal abnormalities associated with unilateral cleft lip. In a single second operation, the following steps seem to give the most satisfactory correction: repositioning the nasal septum in the midline; altering the contour of the alar cartilage on the cleft side; and rotation of the axis of the external naris on the cleft side. The usual result following this combination of procedures is moderate but not complete correction of the abnormality. About 50% of the patients will need a second operation for correction of nasal abnormalities associated with bilateral cleft lip. Satisfactory correction of the bilateral cleft lip nasal deformity is usually obtained by lengthening the columella (which secondarily corrects a flat nasal tip) and narrowing the width of the nose at the level of the alae. Satisfactory restoration to normal is usually obtained by the aforementioned procedure.


Interdental osteotomy for immediate repositioning of dental-osseous elements. The treatment of crowded, poorly aligned, and spaced teeth is most commonly accomplished by orthodontic means. Interdental osteotomy offers a method for the immediate repositioning of dental-osseous elements that may serve as an aid to orthodontic treatment or be used as an independent procedure. The history of the procedure, its indications, planning considerations, surgical methods, and case results are presented.


Psychological considerations in corrective maxillary and midfacial surgery. For the majority of patients with dentofacial deformities, surgical correction results in improved reactions to one's environment. In a few instances, this emotional improvement is lacking or is minimal and may result in a patient's dissatisfaction. The results of evaluation of several specific factors may be used to classify patients into three groups according to probable risk of dissatisfaction. Some negative reactors will respond to supportive measures specifically designed to aid in achieving a smooth postoperative course. In others, surgery should be undertaken only with the close cooperation of a psychiatrist, although occasionally surgery should be deferred indefinitely. By making a planned attempt to evaluate the patient's psychological status and dealing appropriately with that evaluation, the surgeon may increase the number of patients who respond favorably to his treatment and therefore increase his own satisfaction as well.


Clinicopathological conference. Case 13, part 2. Disseminated intravascular coagulation.


Combined anterior and posterior maxillary osteotomy. The combined anterior and posterior maxillary osteotomy is primarily indicated for maxillary alveolar hyperplasia. Treatment planning is somewhat more complex than usual for the combined procedure. A method for developing a treatment plan is presented. In contrast to the anterior maxillary osteotomy, the technique for posterior osteotomy is relatively new and has had several recent modifications. Guidelines are presented for rational selection of a specific combined technique. The results obtained with the combined technique have not been well documented. Nonetheless, results appear to be stable and complications are infrequent.


Modification of the sagittal ramus-split osteotomy for retrognathia. A modification of the sagittal ramus split osteotomy for mandibular advancement has been described. It prevents rotation of the distal fragment, simplifies fixation, and reduces lateral pharyngeal edema.


Acute myelogenous leukemia in children: a preliminary report of combination chemotherapy. Twenty-four children (2 to 21 years) diagnosed as having AML from 1969 to 1972 were randomized to receive either a single combination (COMP or PRAVD) or sequential combination chemotherapy (alternating POMP and PRAVD). Seventeen achieved complete remission. Patients who received POMP alone had the longest median duration of remission (1,400 days) compared to PRAVD (395 days) or POMP-PRAVD (270 days); interpretation of this difference is uncertain, since the numbers in each group are small. Fifteen patients have relapsed, four initially with CNS involvement. Successful reinduction was achieved almost exclusively for patients who had initially received POMP. Survival after first relapse was short. Patients less than 16 years had a median survival of 632 days, compared to 285 days for patiens greater than 16 (p less than 0.05). The high initial induction rate in these patients is encouraging, but the duration remission is inferior to that seen in childhood ALL. Moreover, the slope of the relapse curve is continuous over a five-year period with no definite plateau where it might appear that patients are no longer at risk of relapse. Improved methods for the treatment of childhood ALL and adult AML suggest possible new approaches to AML in children, with prophylactic treatment of central nervous system, late intensification, and immunotherapy.


Dislocation of the condyle into the middle cranial fossa. Surgical intervention by a preauricular approach appears to be the preferred treatment in this rare injury. It does not appear necessary or wise to disimpact the condyle as it presents more of a surgical risk and its presence in the cranial fossa seems to pose no neurological problems. The use of an interposing medium, placed after the teeth are secured in occlusion, appears to be definitely indicated to prevent ankylosis and, hopefully, to eliminate deviation of the mandible. A carved piece of Silastic, designed to conform to the recontoured roof of the glenoid fossa, has produced excellent results in cases of ankylosis; it served well in this case. Silastic has the advantages of being easy to carve, it may be attached to the rim of the fossa, and it is extremely nonirritating; it eventually becomes encased in a fibrous capsule.


Letter: Neck ulceration from CPAP box.

Letter: Neck ulceration from CPAP box.


The development of the periodontal cleft. A clinical and histopathologic study.


Reversible dementia temporally associated with intraventricular therapy with methotrexate in a child with acute myelogenous leukemia. During maintenance therapy with intraventricular methotrexate, progressive dementia developed in a child with meningeal leukemia. Cerebrospinal fluid levels of MTX were in the nontoxic range and neurologic evaluation failed to demonstrate anatomic obstruction, infection, or folate depletion. The patient's symptoms gradually resolved when the methotrexate was discontinued, suggesting that methotrexate neurotoxicity may occur in the absence of an elevated CSF concentration of MTX.


Influence of a chlorhexidine and a zinc mouthrinse on gingivitis. The end point methodology did not indicate a difference between the agents. The prophylaxis effect was only demonstrable through 8 weeks, although the analysis of variance indicated a prophylaxis effect on gingival index throughout the study. An agent effect was not demonstrable in the study. The "positive control," chlorhexidine, did not give the same results in this brushing study as in previous no-brushing studies reported by Loe and by our group. One might conclude that the effectiveness of brushing in reducing gingivitis is greater than the effect of chlorhexidine. Decreasing plaque and gingivitis scores are seen with increasing time, probably reflecting increased subject interest and involvement in the study. Mere involvement in the study apparently produced a beneficial effect on gingival health. This "placebo effect" also has been noted in an earlier study. A similar decrease in plaque scores in a placebo group attributable to a general improvement of oral hygiene was reported by Gjermo and Rolla. The subjects who began the study with no calculus (prophylaxis group) had consistently lower calculus scores than those not given a prophylaxis. This difference became less distinct at later exams, as the treated group developed calculus. The agents, although ineffective under the test regimen produced no adverse effects.


Necrotizing ulcerative gingivitis in children: a 9 year clinical study. Twenty-eight children with ANUG and nine children with noma were studied over the past 9 years. It is concluded that these entities occur only in children from low socioeconomic groups and have a multifactorial etiology consisting of poor oral hygiene and malnutrition. In the case of noma, a prior infection with a viral agent or intestinal parasitism appears to be important predisposing factors.


The pocket mouse (Perognathus longimembris). A unique model of periodontal disease.


The relationship of 17-hydroxycorticosteroid to acute necrotizing ulcerative gingivitis. Eleven patients presenting with acute necrotizing ulcerative gingivitis (ANUG) collected 24-hour urine samples during and after the course of their ANUG. The Porter-Silber technique was used to determine the 17-hydroxycorticosteroid concent of the urine, a physiological measure of stress. All of the patients had significantly higher levels of 17-hydroxycorticosteroid during the course of their ANUG than after it had resolved.


Uremic stomatitis: report of a case.

Uremic stomatitis: report of a case. A case report has been presented demonstrating the influence of chronic renal failure in the development of oral disease. Uremic stomatitis is a disease entity that requires both local and systemic therapy. The primary emphasis is directed toward the correction of the systemic pathology for proper resolution of the oral condition.


The prevalence of periodontal disease in a selected dental population. Sixty-five dental personnel, who presented for voluntary examination at a periodontal screening center, were assessed for plaque accumulation, gingival soft tissue changes, gingival recession and pocket depth. The relationship of these parameters to one another and to a variety of oral hygiene techniques was analyzed. Positive correlations were found between pocket depth and soft tissue changes and also between some of the parameters and use of an interdental stimulator or an oral irrigating device. The nature of the results is discussed.


The accuracy of the Schei ruler: a laboratory investigation. A study has been carried out to assess the accuracy of the Schei ruler for measuring the amount of alveolar bone loss from radiographs. A dried human mandible was used for the purpose of this study. A preliminary test was conducted to achieve a standard radiographic technique. Two sets of radiographs were taken of anterior and posterior segments after successive modification of the height of the alveolar bony crest. These heights were measured directly and also by means of the Schei ruler for each stage, using first the root length, and secondly, the total tooth length, as references for obtaining the percentage of remaining alveolar bone. There are two points which may be concluded from this investigation: 1. The ruler proved to be a sensitive tool for measuring the amount of alveolar bone loss as well as being efficient in this application because of its simplicity and ability to give direct readings of the percentage of the bone lost (or remaining). 2. The use of the total tooth length as a reference for the percentage bone loss, overcomes the difficulties of locating other reference points.


Proceedings: Enhanced pressor response to noradrenaline in human subjects with chronic sympathetic decentralization.


Split thickness flap, apically replaced, with protected linear periosteal fenestration. The split thickness flap, apically replaced, with internal linear periosteal fenestration, is a combination of two known techniques. This procedure is another choice to solve mucogingival problems. The advantages in addition to securing a firmer bond of periosteum to bone and mucosa to periosteum at the selected position are: there is no bone exposed, healing is apparently faster and postoperative pain is minimal. An experimental work, carried out on dogs to study the histological reactions after this procedure, is in progress. The results of these observations will be reported in a future publication.


The relationship between dialy sperm production as determined by quantitative testicular histology and daily sperm output in the stallion. The relationship between daily sperm productions (DSP) and daily sperm output (DSO) was determined in eleven stallions. The DSO was determined by collecting single ejaculates, with an artificial vagina, at 24-hr intervals. The stallions were killed 24 hr after the last collection and the DSP was determined by quantitative testicular histology. The mean DSP was 8-0 X 10(9) (S.E. +/- 0-4 X 10(9), and the mean DSO was 7-0 X 10(9) (S.E. +/- 0-4 X 10(9)). It was estimated that 87% of the spermatozoa produced by the testes were harvested. The correlation between DSP and DSO was 0-80 (P less than 0-01), and between DSP and testis weight was 0-77 (P less than 0-01).


The effect of treatment on lymphomas and childhood solid tumours.


The evolution of the horse.

The evolution of the horse.


Results of long-term storage of stallion semen frozen by the pellet method. Stallion semen frozen by the pellet method showed no significant loss of sperm motility and fertility over long periods of storage in liquid nitrogen. Eighteen of thirty mares conceived after insemination with semen recovered in nine ejaculates from seven stallions and stored for 18 months to 7 years.


Results of insemination of mares with fresh and frozen stallion semen. Artificial insemination using deep-frozen semen was performed on 116 mares in 1973 using twelve ejaculates from eight stallions of the Hanoverian breed. Despite the fact that the quality of the semen used was poor, the majority of the mares inseminated were subfertile and some mares were inseminated during one oestrus only, 44% nevertheless conceived and gave birth to live foals. Of a small group of ten mares inseminated in the same year with fresh semen, seven conceived.


Results of artificial insemination of horses in Poland in the post-war period. Artificial insemination (A.I.) of mares in Poland has not yet been widely applied. Initial attempts were made by research groups between 1945 and 1955 but A.I. of mares was only introduced into the normal practice of A.I. Centres during 1964-67. Intensive research into methods for preserving stallion semen in liquid nitrogen has been undertaken since 1968. Of the total of 3734 mares artificially inseminated in Poland since 1945, 350 were inseminated with frozen semen. The slow progress of A.I. in horses is imputed to the small numbers of people involved in the work, to the conservation of the authorities responsible for breeding, to the wrong choice of stallions for A.I. Centres and, most importantly, to the lack of a simple and reliable method of preservation of stallion semen.


Effect of timing of insemination, numbers of spermatozoa and extender components on the pregnancy rate in mares inseminated with frozen stallion semen. Fertilization rate was highest in mares inseminated with frozen semen within 12 hr of ovulation. Foaling rate was improved (P less than 0-05) by increasing the number of motile spermatozoa inseminated from 40 X 10(6) to 80 X 10(6) but was not further improved by increasing the number to 160 X 10(6) or by increasing the frequency of insemination from once to twice daily. The fertilizing capacity of spermatozoa frozen in one of the hydrogen ion extenders studied was dependent upon relative osmotic pressure and method of freezing (ampoules or pellets). Adjusting glycerol concentration from 7% to 2%, addition of glycerol 15 min before freezing and freezing 2 hr after extension all enhanced the fertilizing capacity of spermatozoa. Pregnancy rate per mare service period was higher (P less than 0-01) for mares inseminated with unextended semen (75%) than for extended semen containing no glycerol (50%) or extended semen containing 7% glycerol (35%). Although wide variability in the fertilizing capacity of spermatozoa from individual stallions was observed when semen was extended or extended and frozen, pregnancy rate was depressed in all stallions. It was concluded, therefore, that hydrogen ion extenders depress fertilizing capacity of stallion spermatozoa immediately after extension and show little promise as semen extenders for short- or long-term storage of stallion semen.


Abnormalities of mating behaviour in domestic stallions. Experimental and clinical observations were made to treat abnormal sexual behaviour. The most common cause of abnormality was mismanagement of the animal; over-use and rough treatment at service and too-frequent ejaculation during winter had a detrimental effect on the behaviour of young stallions. Pain due to injury incurred at copulation or when associated with mounting attempts was also a common cause of impotence. Most impotent stallions responded well to re-training and recovery can be achieved without pharmacological treatment in most cases.


Ejaculatory disorders of the stallion.

Ejaculatory disorders of the stallion. Ejaculatory disorders of the stallion seem to occur more frequently than hitherto accepted. The condition is manifested differently in individual stallions from normal copulation without ejaculation to an abnormal pattern of copulation without or with occasional ejaculation. The condition is probably caused by a functional disturbance of the nervous mechanism which controls the ejaculatory process, and may be caused by environmental or other factors. Eleven cases of ejaculatory disorders in normal healthy stallions were investigated and three of these animals recovered after simple correction of environmental factors, including the number of mares served. Of the eight stallions which did not respond to environmental changes, one recovered after treatment with pilocarpine and one after treatment iwth ephedrine. Possible causes of failure of the nervous regulation of the reproductive tract are discussed.


Immature germ cells in the semen of thoroughbred stallions. Small but significant numbers of primary and secondary spermatocytes and spermatids have been observed in the semen of some Thoroughbred stallions. Extensive histological examination of the testes of affected animals has not been undertaken but in one young stallion which died as the result of a leg injury, the premature dehiscence of these cells seemed to be related to segmental defects within the seminiferous tubules. The causes of lesions leading to premature shedding of germ cells are discussed.


Reproduction in feral horses.

Reproduction in feral horses. A behavioural study of feral horses was conducted on the Pryor Mountain Wild Horse Range in the western United States. All 270 horses on the Range were identified individually. The sex ratio was nearly balanced. Foal to adult female ratio was 43-2:100. Morality was concentrated among foals and old horses. Horses were organized as forty-four harem groups each with a dominant stallion, one to two immature stallions, one to three immature mares, one to three adult mares and their yearling and foal offspring, and 23 bachelor groups of one to eight stallions. Harem groups were quite stable year-round because of dominance and leadership by the stallions and group fidelity by mares and their offsring. Most changes occurred during the breeding season and involved immature females. Defeat of dominant stallions was infrequent. Immature males were tolerated because of their submissive behaviour. Bachelor stallion groups were inherently unstable. Mares came into heat after foaling in May/June, and were mated by harem stallions only.


Recent observations concerning Klebsiella infections in stallions. A high incidence of Klebsiella contamination in German 'Warmblut' and Thoroughbred stallions is reported. The organism was recovered from the nostrils, prepuce, pre-ejacultory secretion and, in some cases, on the body surface, in the faeces and on the ground of the covering (mating) yard. Fertility was not affected. However, differences of virulence were observed and Type 5 proved to be the most pathogenic.


Diagnosis and treatment of haemospermia in the stallion. Haemospermia caused infertility in the stallion and frequently results from a urethritis in the area of the ejaculatory ducts. Urethroscopic examination, urethrography, bacterial and viral cultures, biopsy, surgery of the urethra and histocytological examination should be used for diagnosis and it is essential that the exact cause and location of the haemorrhage be known before treatment is initiated. Optimal treatment includes sexual rest and appropriate antibiotics used systemically in conjunction with local medication of the urethra. Cauterization of the urethra with silver nitrate solution should be avoided.


Unique aspects of the reproductive cycle of the mare.


The oestrous cycle of the mare.

The oestrous cycle of the mare. In eleven non-pregnant mares examined for 2 years, oestrous cycle length was 20-6 days (range 13 to 34) excluding any anoestrous periods. The duration of oestrus was 5-7 days (range 1 to 24); from February to May it was 7-6 days (range 2 to 24) and from May to November 4-8 days (range 1 to 10). The majority of ovulations occurred between 16.00 and 08.00 hours and 78% of the mares ovulated within 48 hr of the end of oestrus. Mean follicular diameter was 45 mm on the day of ovulation and there was a 25-5% incidence of multiple ovulations. It was uncommon for oestrus to occur without ovulation, whereas ovulation without oestrus occurred in 6/11 mares, including one mare which ovulated without oestrus on 32/34 occasions. The CL was palpable after ovulation for 8-9 days (range 1 to 18). Dioestrus averaged 15-4 days (range 6 to 25). Ovulations during dioestrus, unaccompanied by signs of oestrus, occurred in 10/11 mares but cycle length was not affected. A syndrome of spontaneous prolongation of the CL, accompanied by follicular activity, without any signs of oestrus for periods of 2 to 3 months was observed in six of the mares.


A review of the influence of nutrition upon the oestrous cycle and early pregnancy in the mare. Attention is drawn to the beneficial effect of improved nutrition during winter and early spring on the ovarian activity of mares. Furthermore, the necessity of an adequate plane of nutrition during early pregnancy to prevent embryonic resorption is stressed.


Relationship between the morphology of and progesterone production by the corpus luteum of the mare. The histology of the growing, secreting and regressing CL of thirty-five cycling and early pregnant mares with known breeding histories was studied by light microscopy. Thecal cells are best developed a few days before ovulation. They regress very quickly and within 24 hr after ovulation all remaining thecal cells are in an advanced stage of degeneration. Hypertrophy and luteinization of the granulosa cells commences 10 hr after ovulation and maximum size (37-5 mum) is reached later. The luteal tissue enlarges mainly through hypertrophy of the lutein cells. Two types of lutein cells are found in the CL, a large light-staining cell and a small dark-staining cell. Degeneration of the lutein cells in the non-pregnant mare commences on Day 12 after ovulation and in the pregnant mare on Day 38 after ovulation. The primary CL of pregnancy regresses after the secondary CL are formed. The progesterone concentration in the peripheral plasma is closely correlated with the morphological changes in the CL.


Relationship between luteal function and metabolic clearance and production rates of progesterone in the mare. The functional activity of the equine CL was measured by its ability to convert [4-14C]3beta-hydroxy-5-en-20-one to [4-14C]pregn-4-en-3,20-dione. The capacity of homogenates of CL of different ages followed the temporal pattern of plasma progestagen concentrations. In ten mares which ovulated twice at intervals of 0 to 9 days in the same cycle, the conversion capacity of the CL from the second ovulation was similar to that from the first ovulation. After adjusting for age, the CL from the first of two ovulations had a similar conversion capacity as that resulting from a single ovulation. Plasma metabolic clearance rates of progesterone were similar on the 8th day after ovulation in mares having one and two ovulations. Progesterone production rates were also similar in mares with one and two ovulations. A two-component disappearance curve was observed following cessation of the [3H]progesterone infusion in mares that ovulated once or twice in the same cycle.


Effect of exogenous progesterone on its endogenous levels: biological half-life of progesterone and lack of progesterone binding in mares. The disappearance rate of progesterone from blood plasma of an ovariectomized mare was rapid and occurred in three phases. The half-life of the first component was 2-5 min and that of the second was 20 min; the half-life of the much slower third component was not measured. Progesterone, administered to ovariectomized and deeply anoestrous mares at the rate of 150 or 300 mg/day, maintained maximal peripheral levels of 6 to 8 ng/ml. Physiological levels were reached in 21 days using a dose of 150 mg and in 11 days with 300 mg daily. After withdrawal, circulating levels dropped rapidly. Blood plasma of mares appears to lack progesterone-specific binding proteins. It is concluded that the problem of habitual abortion and its treatment in mares need re-evaluation.


The cycle of oestrus, ovulation and plasma levels of hormones in the mare. The duration of the oestrous cycle and day of ovulation were recorded in six mares which were used for concurrent assay of plasma levels of sex steroids and pituitary LH concentration. Peak of progesterone were reached during dioestrus and those of oestradiol and androstenedione occurred 2 days before ovulation and were in decline on the day of ovulation. Plasma oestrone remained constant (between 9 and 12 pg/ml) throughout the cycle. Plasma LH rose to a maximum near to the time of ovulation, and thereafter decreased gradually until mid-dioestrus. The pattern of secretion is compared with that reported in other domesticated animals.


The evaluation of stallion semen in aspects of fertility control and its use for artificial insemination. Choice of the best methods for semen examination is dictated by the purpose of the examination, whether it be to assess the fertility of an individual stallion or to evaluate individual semen samples for routine purposes. In the author's experience of examining stallion semen, emphasis should be placed upon morphological examination, sperm cinematography and survival tests in vitro. Special problems concerning examination of frozen semen are discussed and the ultrastructure of spermatozoa frozen in the presence and absence of glycerol is described.


Plasma LH levels in the mare during the oestrous cycle. Plasma levels of LH were determined by heterologous radioimmunoassay utilizing highly purified equine LH as standard. Samples were taken regularly from eleven mares for twenty-six oestrous cycles over a period of 10 weeks. The mean cycle length was 20-5 +/- 3-1 (S.D.) days, and ovulation occurred on average 4-3 +/- 1-6 (S.D.) days from the time heat was first detected. Levels of LH were persistently low from Days 5 to 16 of the cycle (ovulation = Day 0). They then increased slowly over a number of days and continued to rise beyond the levels observed at any time during the immediate preovulatory period or the day of ovulation. A significant decrease from peak levels was not observed until the 3rd day after ovaulation, from which time levels continued to decline toward dioestrous values by an apparent first-order decay process with a half-life of 1-8 days. The pattern of plasma LH in the mare differs from that reported for other species and it is suggested that persistance of high concentrations of LH results from a long half-life of the endogenous LH. This in turn may be responsible for the relatively large number of second ovulations detected in many oestrous cycles.


Levels of LH, prolactin and oestrogens in the serum of post-partum mares. The levels of LH, prolactin and oestrogen were measured by radioimmunoassay in serum obtained from six mares during the post-partum period, and LH was also assayed in blood samples collected at 6-hr intervals from four normal cyclic mares during oestrus and at daily intervals during dioestrus. The concentrations of oestrogen and LH suggested that the mares were having ovulatory cycles during the post-partum period irrespective of behavioural oestrus, and the levels of prolactin seemed to rise in association with probable ovulatory LH peaks. In these mares levels of LH had increased significantly (P less than 0-05) by Day 4 of oestrus and reached a peak (140 +/- 48 ng/ml) about 1 day before the end of oestrus. They then declined rapidly and remained at basal levels (10 to 20 ng/ml) during dioestrus.


Serum concentrations of FSH, LH and progesterone during the oestrous cycle and early pregnancy in the mare. Heterologous radioimmunoassays were developed for equine FSH and LH. Serum concentrations were measured in twenty-three mares throughout the oestrous cycle and early pregnancy. FSH concentrations were raised fivefold by 'surges' rather than 'spiked', occurring at 10- to 11-day intervals during the oestrous cycle and early pregnancy. The late oestrous/early dioestrous surge of FSH appeared to initiate development of up to twenty follicles. The mid-dioestrous surge may be important for the further development of follicles destined to ovulate 10 to 13 days later. Levels of LH were increasing by the onset of oestrus and reached their maximum 1 to 2 days after ovulation. This rise in LH may stimuate maturation of the follicle throughout oestrus. An inverse relationship between progesterone and LH levels occurred, suggesting a negative feedback, but there was no such relationship between FSH and progesterone concentrations.


Urinary oestrogen and plasma progesterone levels in non-pregnant mares. Eight mares were observed clinically for 14 months to detect oestrus and ovarian activity, and assays of urinary oestrogens and plasma progesterone were performed. Cyclical ovarian activity occurred during 60% of the experimental period. Persistent luteal activity was found over 20% of the period and for the rest of the time activity was absent. Cyclical activity was characterized by the alternation of periods of low and high progesterone levels corresponding to the follicular and luteal phases of the ovarian cycle. During the follicular phase, urinary oestrogen levels increased to a maximum of 463 +/- 296 ng/ml 2 days before ovulation. The duration of the interval from complete luteolysis to ovulation (6-3 +/- 2-7 days) was correlated with oestrone peak values (r = 0-44) and with oestrone levels at the beginning of the low progesterone phase (r = -0-36). High oestrogen levels were recorded during persistent luteal activity which occurred more frequently in summer. Ovarian inactivity was more frequent in winter and was characterized by very low progesterone and low oestrogen (less than 50 ng/ml urine) levels. Some individual and seasonal effects were studied.


Influence of intrauterine saline infusion upon the oestrous cycle of the mare. The effect of intrauterine saline on reproductive function was studied by infusion of mares in anoestrus, dioestrus, oestrus and prolonged dioestrus. Anoestrous mares were unaffected except near the beginning and end of the breeding season when anovulatory heats were induced. Dioestrous mares infused between Days 5 and 9 returned to heat an average of 3-8 days earlier than expected, and infusions during dioestrus were followed by ovulatory heats of normal fertility. Three mares in prolonged dioestrus showed ovulatory heats within 3 to 9 days of infusion. Infusions during oestrus had no appreciable effect. Repeated infusions were clinically harmless but post-infusion bacteriological swabs from the uterus were positive. In two cases studied, infusion was followed by a fall in peripheral plasma progestagen concentrations. Evidence was obtained that vaginal and cervical dilatation and oxytocin were not involved in the mechanisms and it is postulated that the luteolytic effect of intrauterine saline is mediated by prostaglandin.


Oestrogen excretion in mares in relation to various reproductive states. The rate of urinary oestrogen excretion was studied in four ovariectomized mares. In two animals ovariectomized when urinary oestrogen concentration was high, levels fell to a minimun within 48 hr. Intramuscular injection of oestradiol-17beta produced maximum urinary oestrogen levels within 3 to 6 hr and a return to minimum detectable levels within 24 hr. The major urinary oestrogen in mares was oestrone. In nine maiden mares studied between September and June, the cycle, the durations of dioestrus and oestrus, and the time of ovulation were similar in autumn (September to December) and spring (January to June). All nine mares had periods of anoestrus and 'shallow' and 'deep' forms of this condition were observed. In all cyclic mares, urinary oestrogen excretion showed a gradual rise from dioestrous levels beginning 6 to 7 days before ovulation. A rapid and highly significant (P less than 0-001) fall in oestrogen excretion occurred on the day of ovulation and the day after. Maximum urinary oestrogen levels were twice as high in spring than in autumn cycles.


The influence of intrauterine saline infusion on luteal function and cyclical activity in the mare. Intrauterine saline infusion in the dioestrous mare shortened the ovulatory interval by inducing premature luteolysis. Plasma progestagen levels began to decrease approximately 1 day after the infusion and had declined to less than 1-0 ng/ml in 4 days. The CL, including others formed from ovulations during dioestrus, must be 4 to 5 days old before intrauterine saline will induce luteolysis. Of 10 mares infused on Day 4 or 5 after ovulation, only six had a shortened ovulatory interval. Of 10 mares infused on Day 6 or 7 after ovulation, seven had a shortened ovulatory interval and three failed to respond due to the occurrence of a dioestrous ovulation near the time of infusion. In those mares which responded to treatment, the interval from saline infusion to the beginning of oestrus and to ovulation was 5 to 6 days and 9 to 10 days, respectively.


Effects of artificial light on the oestrous cycle of the mare. Two groups, each of seven pony mares, were maintained from 17 October to 15 February (120 days) in the University Biotron where temperature and daily photoperiod were regulated to simulate normal conditions for that period (control group) or those normally applicable from 1 March to 1 July (treated group). Follicular growth, ovulation rate and oestrous behaviour were determined daily by rectal palpation, and by teasing with a stallion. By Day 69 of treatment, all ovarian end-points (number of follicles greater than 10 mm, number of follicles greater than 20 mm, average follicle diameter and diameter of the largest follicle) were significantly greater in treated than control mares. Oestrous behaviour was evident in all the mares in the treated group, but was not recorded in any of the control group mares; two of the treated mares ovulated. After removal from the environmental control chambers, the experimental and control mares first ovulated on an average of 147 days and 227-6 days, respectively, after the beginning of the project. Mares in both groups cycled regularly after the first ovulation and were in anoestrus again at about the same time in the following winter.


The use of prostaglandin F2alpha-tham salt in mares in clinical anoestrus. Seventy-three Standardbred and Thoroughbred mares in clinical anoestrus during the breeding season were treated with PGF2alpha. The mares were divided into four categories; foaling, barren, maiden and unknown. The response was consistent in all groups. Mares at Days 2 to 4 of dioestrus showed no decrease in plasma progesterone levels, and those at Days 6 to 8 showed a return of progesterone to baseline levels (less than 1 ng/ml) in 24 to 48 hr after treatment. Plasma progesterone levels returned to basal levels in 24 to 48 hr in 93% of mares; progesterone levels had not changed by 96 hr in 7% of the treated mares. Behavioural oestrus was detected in 71% of treated mares an average of 4-4 days after treatment, and ovulation occurred in 86% at an average of 8-9 days. Pregnancy occurred in 55-5% of the PGF2alpha-treated mares after an average of 1-7 services during the induced oestrus.


Oestrus, ovulation and plasma hormones after prostaglandin F2alpha in mares. The luteolytic effect of PGF2alpha, administered by intrauterine infusion or subcutaneous injection during early dioestrus, was observed in mares of mixed breeds. An infusion of 10 mg on Days 7 to 9 after ovulation caused a sharp fall in plasma progesterone levels and induced oestrus and ovulation. Oestrus was significantly longer than in the natural cycle but the time of ovulation in relation to the end of oestrus was normal. The time of return to oestrus following luteolysis was not dependent on the amount of PGF2alpha within the range of doses given. Luteolysis could be induced as early as Day 5 following natural ovulation.


Effects of prostaglandin F2alpha on the oestrous cycle and pregnancy in mares. Several experiments indicated that prostaglandin F2alpha (PGF2alpha) has luteolytic and abortifacient properties in mares. A single subcutaneous injection of 1-25 mg PGF2alpha on Day 6 of dioestrus was as effective as 10 mg PGF2alpha in inducing luteolysis. Oestrus and ovulation appeared to be synchronized when a single injection of 1-25 mg PGF2alpha was given on Days 7, 10 or 13 after ovulation but not on Days 1 or 4 after ovulation or on Day 2 of oestrus. Intramuscular administration was as effective as subcutaneous administration and 1-25 mg PGF2alpha was the minimal effective systemic dose to induce luteolysis. Administration of PGF2alpha into the uterus or directly into the CL did not improve the luteolytic efficacy of the intramuscular injection of PGF2alpha. All thirteen mares aborted following injections of 2-5 mg PGF2alpha at 12-hr intervals; an average of 3-7 injections were given before abortion occurred.


The effect of rectal palpation on the fertility of cyclic mares. The effect of rectal palpation of fertility of non-lactating, normal cyclic mares was studied over 3 years. During the first year (1971), the conception rates in mares after daily paplaption during oestrus only, and during oestrus and the first 50 days of pregnancy, were not significantly lower (P greater than 0-05) than the conception rates recorded in mares not palpated. No abortions could be attributed to palpation. Oestrus lasted longer (P less than 0-05) in non-palpated than palpated mares. During the second year (1972), first-cycle pregnancy rates in two groups of mares palpated daily during oestrus were lower (P less than 0-05) than those of mares not palpated. Daily palpation and insemination on the palpator's recommendation resulted in fewer (P less than 0-05) inseminations per cycle than in mares inseminated every other day of oestrus. During the third year (1973), the difference of first-cycle conception rates between mares palpated on alternate days of oestrus and those not palpated was not significant. Throughout the three years of the study, first-cycle conception rates following insemination with undiluted semen were higher (P less than 0-025) in non-palpated mares than in palpated mares (45-7 versus 79-2%).


The use of prostaglandin F2alpha in controlling the oestrous cycle of the mare and steroid changes in the peripheral blood. Prostaglandin F2alpha (PGF2alpha), administered by untrauterine infusion and intramuscular injection, was used to induce oestrus and ovulation in non-cyclic mares. A satisfactory response rate (80% or more) was obtained and the dose (2-5--7-5 mg) and the time taken for ovulation to occur (up to 9 days) was the same irrespective of the route of administration. Only about one-half of the mares conceived to mating at the induced oestrus but the low conception rate could be attributed to the infertile condition of the mares. Plasma progesterone remained at basal levels after PGF2alpha and oestrogen levels were inconsistent. The use of PGF2alpha in the treatment of severe endometritis was successful in one mare.


Synchronization of oestrus in mares with a prostaglandin analogue and HCG. Following an initial observation period of 13 days when plasma progesterone levels were determined, synchronization of oestrus and ovulation was investigated in thirty-three mares treated with a prostaglandin analogue ('Equimate') and HCG. Two courses of treatment were given 8 days apart and each consisted of a single intramuscular injection of Equimate (250 mug) followed 6 days later by an intramuscular injection of HCG (2500 i.u.). The first course was designed to remove all luteal tissue and to induce ovulation of any follicles that developed in response to the withdrawal of progesterone. The second course had the effect of synchronizing oestrus and ovulation following luteolysis of the induced CL in all the mares. A high proportion of treated mares responded by ovulation within 24 and 72 hr after the second HCG injection and provided fertility was not disturbed, the prognosis for a high success rate by the double treatment was good. The plasma progesterone level is a reliable criterion of ovulation and would replace the need for the clinical procedures normally employed to determine the onset of oestrus and follicle rupture.


Effects of progesterone on reproductive function in mares after parturition. The injection of 100 mg of progesterone/day from Days 5 to 14 after foaling blocked or delayed oestrus and ovulation in 6/9 mares; the remainder ovulated during treatment without showing oestrus. Urinary oestrogen concentrations in these mares were highest between Days 9 and 15 after foaling but the peak levels were only about half those seen in untreated mares during the post-partum oestrus and ovulation. The injection of 200 mg progesterone/day blocked oestrus and ovulation in two mares but did not depress oestrogen excretion maxima any further. Follicles prevented from developing beyond a cricital stage lost their ability to ovulate after progesterone withdrawal. No significant histological differences were found in endometrial biopsies taken from progesterone-treated and control mares on Days 5, 10 and 15 after foaling. Injection of 100 mg progesterone between Days 1 and 10 after foaling delayed oestrus and ovulation in all six mares. Conception occurred in 8/12 progesterone-treated mares as the result of mating at oestrous periods which were delayed until Days 15 to 28 after foaling.


Some clinical observations on the effect of an implant of oestradiol benzoate in brood mares. The clinical effects and therapeutic value of a 500 mg implant of oestradiol benzoate was observed in thirty-nine Thoroughbred brood mares showing various abnormalities of the ovary and/or the reproductive tract. Sixteen similarly affected, untreated mares acted as controls. The implant was inserted during the early part of the normal anoestrous period and was removed 6 to 10 weeks later. The conception rate among the treated group (59%) during the onset of the ensuing breeding season was significantly higher (P less than 0-02) than that in the control group. The value of this form of treatment in septic endometritis and as an anabolic aid in cases of immaturity is also discussed.


The effect of HCG on duration of oestrus, ovulation time and fertility in mares. Two experiments were conducted to determine the effects of HCG on duration of oestrus, dioestrus, the length of the oestrous cycle, the time of ovulation and fertility in non-lactating mares. In the first experiment, the injection of HCG was repeated for three successive cycles. Mares injected with 2000 i.u. HCG on Day 2 of oestrus during their first cycle had a shorter oestrus and ovulated sooner than untreated control mares, but in the third cycle, treated mares had a longer oestrus and ovulated longer after the onset of oestrus than controls. In the second experiment, one intramuscular injection of 3300 i.u. HCG was given 24 hr before the first insemination in the first cycle. Oestrus was shortened by 3-1 days, but there was no difference in pregnancy rate between treated and control mares (61-1 versus 63-9%). During the two cycles following injection, the conception rate in the treated mares was higher. The number of inseminations/cycle to effect fertility was significantly less over three cycles in the treated mares.


Control of fertility in Thoroughbred horses in West Germany. A central control system for German Thoroughbred horses is described. Autumn examination of mares and stallions enables them to be classified according to breeding potential. The results of 25 years of study are reported.


Pelviscopy in the mare.

Pelviscopy in the mare. A method of endoscopic examination of the internal genital (pelvic) organs of the mare is described. Special emphasis is placed on the induction of artificial pneumoperitoneum and the installation of an endoscopic peritoneal fistula device for prolonged observation. The potential of pelviscopy in the mare as a diagnostic aid, a new device for research in equine reproduction and as an auxillary aid to teaching is discussed.


The distribution of delta5-3beta-hydroxysteroid dehydrogenase in the graafian follicle of the mare. Graafian follicles of various sizes obtained from mares at different stages of the oestrous cycle were examined histologically and histochemically for delta5-3beta-hydroxysteroid dehydrogenase (3beta-HSD) activity and related enzymes. The 3beta-HSD activity was not found in the theca interna of any follicles but was present in the membrana granulosa of well-vascularized large follicles in the late luteal phase of the cycle and at oestrus. These findings indicate that pregnenolone cannot be converted into progesterone in the theca interna. It is suggested that this conversion occurs in the membrana granulosa and that progesterone then passes into the theca interna where it is converted into oestrogen. Participation of both granulosa and thecal cells in oestrogen production is also discussed from a morphological view-point.


The frequency of infertility in thoroughbred mares. In a group of 852 Thoroughbred mares, 69-7% had foals which survived beyond 6 weeks, 7-1% had dead, premature or full-term foals and 1-1% had foals which died within 6 weeks after birth. Possible factors which may have influenced these data are mentioned.


Survey of reproductive efficiency in the Quarter-horse and Thoroughbred. Reproductive efficiency was evaluated for 838 Quarter-horse mare-years on five farms and 939 Thoroughbred mare-years on seven farms over 4 years. The pregnancy  rate from first service was 51% for Quarter-horse mares and 43% for Thoroughbred mares (P less than 0-05). The cumulative pregnancy rate after five services was 85% for Quarter-horse and 77% for Thoroughbred mares (P less than 0-05). First-service-period pregnancy rates were 44, 40 and 54% for maiden, barren and foaling mares, respectively. Cumulative pregnancy rates after five service-periods were 84, 74 and 84% for maiden, barren and foaling mares, respectively. The pregnancy rate for foaling mares served during foal heat was lower (P less than 0-05) than the first-servicd pregnancy rate of foaling mares served after the foal heat. Less than 40% of the maiden mares, less than 50% of the barren mares and less than 30% of the foaling mares were submitted for their first-service-periods by the end of March.


Clinical management of equine ovarian neoplasms. The rarity of equine ovarian neoplasms is attested to by the lack of reports in the literature. However, sixteen cases have been diagnosed at the Iowa State University Veterinary Hospital in the last 3 years and, of these, the granulosa-cell tumour was the most common. A study of the clinical and subsequent histories of these and other mares reveals some common findings as to age, breed, reproductive status, clinical signs, and post-surgical reproductive capability.


The site of ovulation in the mare.

The site of ovulation in the mare. Serial photography of the ovary of a mare by periodic surgical exteriorization of the ovary and peritonescopy in situ revealed that the ovulatory fossa is the site of ovulation in this species.


Endometrial biopsy as a guide to diagnosis of endometrial pathology in the mare. A safe and simple technique of endometrial biopsy is described which the results suggest is a useful adjunct to the diagnosis of suspected pathological conditions of the uterus. In conjunction with other clinical data and a knowledge of the breeding history, histopathological findings form a basis for prognosis and treatment of the subfertile mare. A system of classification is presented as a basis for continuing work on the correlation of endometrial histopathology with fertility and breeding potential.


Selected pathological changes of the mare uterus and ovary. Focal enlargements of the uterus are palpable through the rectal wall and have various aetiology. Aspects of their diagnosis, possible pathogenesis, significance and treatment are presented. Lymphatic lacunae appear to be quite common in older mares and may occasionally give rise to large endometrial cyst, but more frequently cause widespread change throughout the uterine horns. Three unusual ovarian abnormalities are presented, a large, oestrogen-producing granulosa cell tumour, an oestrogen-producing large follicle in a 4-month-old filly, and an ectopic progesterone-producing adrenal structure bordering on neoplasia.


Prognostic value of endometrial biopsy of the mare.


Candida infection of the genital tract in thoroughbred mares. This paper describes sixteen cases of Candida infection of the genital tract in Thoroughbred mares. Clinical signs and histopathological lesions of the disease are described and the results of treatment with Lugol's solution and Nystatin are given.


Endometritis, a common cause of infertility in mares. Infertility, resulting from failure to conceive during the preceding breeding season, was caused by various forms of endometritis in forty-four mares of Highland and Arabian breeds in Yugoslavia. Chronic mucopurulent and latent catarrhal endometritis occurred most frequently. Douching of the uterus on alternate days for 9 days with warm and cold sterile salt solutions (ranging from 7% to 1% w/v) in the early autumn resulted in conception in 47-7% of mares at an average of 15-2 days after the onset of treatment, and another 36-7% becoming pregnant in the following spring. Mating at the wrong stage of the oestrous cycle and too frequent mating during oestrus were judged to be the most common causes of endometritis in the mares examined.


A review of cytogenetics in equine reproduction. The karyotype of the horse consists of 64 chromosomes; 18 pairs have a terminal centromere and 13 pairs a non-terminal centromere. Identification of individual chromosomes is enhanced by the use of band-staining techniques which allow recognition of minor structural rearrangements of chromatin material. Seven previously reported cases of male pseudohermaphroditism with chromosome studies are reviewed. Three were genetic females, one was basically an XX/XY chimaera, one was an XX/XXY chimaera, and one was an XXXY. Also reviewed is an infertile mare with 63 chromosomes and no distinguishable sex chromosomes and a mare with juvenile genitalia and XO/XX sex chromosomes. It is postulated that, in the future, additional chromosome abnormalities will be found associated with maldevelopment of the equine reproductive system and as a cause of early embryonic death and abortion.


An intersex (male pseudohermaphrodite) horse with 64XX/XXY mosaicism. The clinical, pathological and chromosomal findings in a male pseudohermaphrodite horse are reported. This animal appeared to be a female but showed strong male sexual behaviour. A small penis emerged from a rudimentary vagina. Two small testes were present in the abdomen and undifferentiated seminiferous tubules contained only supporting cells. No uterus was found. Culture of peripheral blood leucocytes revealed a 64XX/65XXY mosaicism.


Cytogenetic studies of three equine hybrids. A detailed investigation of testicular meiosis in a mule, a hinny and a Przewalski horse/domestic horse hybrid were made. Abnormalities of pairing were observed in the mule and hinny in most germ cells at the pachytene stage of meiotic prophase, and spermatogenesis was alsmot totally arrested. A few mature spermatozoa were recovered from the ejaculate and epididymal flushings of the hinny. The Przewalski horse/domestic horse hybrid was fertile and showed normal spermatogenesis. Chromosome banding studies showed a close homology between the karyotypes of the Prezwalski horse (Equus przewalskii, 2n = 66) and the domestic horse (E. caballus, 2n = 64), and it is evident that a single Robertsonian translocation has occurred transforming four acrocentric chromosomes of E. przewalskii into two metacentric chromosomes in E. caballus. The investigations showed that a trivalent is formed at meiosis in the hybrid (2n = 65), segregation from which gives two classes of genetically balanced spermatozoa. Both of these are capable of producing normal offspring if they fertilize the eggs of a domestic mare.


Bacteriostatic activity of the mare uterus: a progress report on immunoglobulins.


Chromosome abnormalities as a cause of infertility in mares. Chromosomal abnormalities have been detected in seven mares isolated by their poor reproductive performance. All had small or rudimentary gonads and absent or irregular oestrous cycles. Two mares had an XO genotype, one was a 65,XXX female and another a 64,XY sex-reversed female. Two other mares were sex chromosome mosaics of the 63,X/64,XX type. The seventh mare showed a normal female karyotype but a small extra autosomal fragment was found in a few cells.


Gonadal dysgenesis in the mare.

Gonadal dysgenesis in the mare. Five phenotypically normal but infertile mares were studied; four had karyotypes of 63XO, and one was a 25,64XX/13,63XO mosaic. The mares exhibited small uteri and has small ovaries that lacked germ cells and consisted primarily of undifferentiated ovarian stroma. These cases demonstrate that chromosome analysis is an important technique for the diagnosis of some forms of equine infertility.


The ultrastructure of endometrial cups in pregnant mares. Electron microscopy and immunofluorescence techniques were used to study the various epithelial cells in the endometrial cups of ten pregnant mares, and in the uterine epithelium of one non-pregnant mare. Evidence was obtained which suggested that epithelial gland cells within the endometrial cups, as distinct from the hypertrophied decidual-like cells in the cup, may synthesize PMSG. The suggestion does not agree with the findings of other workers in the fetal origin (chorionic girdle cells) of this gonadotrophin.


Morphology of stallion spermatozoa.

Morphology of stallion spermatozoa.


Some aspects of endometrial cup formation and PMSG production. Two females of heterosexual pairs of chimaeric horse twins were fertilized by their co-twin brother and PMSG production examined during gestation. Four pregnancies developed in one mare and two in the other. The levels of PMSG were high in both mares and remained detectable in the peripheral blood until 220 and 265 days of gestation. The fetal membranes of one mare contained remnants of cup secretion with PMSG activity at term. The findings support the thesis of Allen & Moor (1972) that the endometrial cups are of fetal origin and that they are destroyed by immunological mechanisms.


Origin and histogenesis of equine endometrial cups. Biochemical and morphological studies were carried out to determine the origin and histogenesis of endometrial cups in mares. A wide range of fetal and maternal tissues were cultured in vitro and their ability to secrete gonadotrophin (PMSG) was monitored. High levels of PMSG were produced in culture only by cells from the restricted area of the equine trophoblast known as the chorionic girdle which is an annular band of highly specialized cells at the junction of the allantois and the regressing yolk sac. The morphological appearance of girdle cells after cultivation in vitro and after allogeneic grafting to the uterus or testis was identical to that of endometrial cup cells. Firm attachment between the cells of the chorionic girdle and the adjacent endometrium occurs on Day 36. Girdle cells then rapidly invade and phagocytose the endometrial epithelium, and migrate into the endometrial glands and the uterine stroma where they differentiate into large, sessile endometrial cup cells.